956 resultados para nonstructural protein 5
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The Myc oncogene regulates the expression of several components of the protein synthetic machinery, including ribosomal proteins, initiation factors of translation, RNA polymerase III and ribosomal DNA(1,2). Whether and how increasing the cellular protein synthesis capacity affects the multistep process leading to cancer remains to be addressed. Here we use ribosomal protein heterozygote mice as a genetic tool to restore increased protein synthesis in E mu-Myc/+ transgenic mice to normal levels, and show that the oncogenic potential of Myc in this context is suppressed. Our findings demonstrate that the ability of Myc to increase protein synthesis directly augments cell size and is sufficient to accelerate cell cycle progression independently of known cell cycle targets transcriptionally regulated by Myc. In addition, when protein synthesis is restored to normal levels, Myc- overexpressing precancerous cells are more efficiently eliminated by programmed cell death. Our findings reveal a new mechanism that links increases in general protein synthesis rates downstream of an oncogenic signal to a specific molecular impairment in the modality of translation initiation used to regulate the expression of selective messenger RNAs. We show that an aberrant increase in cap- dependent translation downstream of Myc hyperactivation specifically impairs the translational switch to internal ribosomal entry site ( IRES)- dependent translation that is required for accurate mitotic progression. Failure of this translational switch results in reduced mitotic- specific expression of the endogenous IRES- dependent form of Cdk11 ( also known as Cdc21 and PITSLRE)(3-5), which leads to cytokinesis defects and is associated with increased centrosome numbers and genome instability in E mu-Myc/+ mice. When accurate translational control is re- established in E mu-Myc/+ mice, genome instability is suppressed. Our findings demonstrate how perturbations in translational control provide a highly specific outcome for gene expression, genome stability and cancer initiation that have important implications for understanding the molecular mechanism of cancer formation at the post- genomic level.
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There is a need for new adjuvants that will induce immune responses to subunit vaccines. We show that a short peptide, named Hp91, whose sequence corresponds to an area within the endogenous molecule high mobility group box (HMGB1) protein 1 potentiates cellular immune responses to peptide antigen and cellular and humoral immune responses to protein antigen in vivo. Hp91 promoted the in vivo production of the immunomodulatory cytokines, IFN-gamma, TNF-alpha, IL-6, and IL-12 (p70), as well as antigen-specific activation of CD8+ T cells. These results demonstrate the ability of a short immunostimulatory peptide to serve as an adjuvant for subunit vaccines. (C) 2010 Elsevier Ltd. All rights reserved.
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Aims: To evaluate the C-reactive protein (CRP) and interleukin-6 (IL-6) as diagnostic tools for early onset infection in preterm infants with early respiratory distress (RD). Methods: CRP and IL-6 were quantified at identification of RD and 24 h after in 186 newborns. Effects of maternal hypertension, mode of delivery, Apgar score, birth weight, gestational age, mechanical ventilation, being small for gestational age (SGA), and the presence of infection were analyzed. Results: Forty-four infants were classified as infected, 42 as possibly infected, and 100 as uninfected. Serum levels of IL-6 (0 h), CRP (0 h), and CRP (24 h), but not IL-6 (24 h) were significantly higher in infected infants compared to the remaining groups. The best test for identification of infection was the combination of IL-6 (0 h) 36 pg/dL and/or CRP (24 h) 0.6 mg/dL, which yielded 93% sensitivity and 37% specificity. The presence of infection and vaginal delivery independently increased IL-6 (0 h), CRP (0 h) and CRP (24 h) levels. Being SGA also increased the CRP (24 h) levels. IL-6 (24 h) was independently increased by mechanical ventilation. Conclusions: The combination of IL-6 (0 h) and/or CRP (24 h) is helpful for excluding early onset infection in preterm infants with RD but the poor specificity limits its potential benefit as a diagnostic tool.
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In the present study, the participation of the Na(v)1.8 sodium channel was investigated in the development of the peripheral pro-nociceptive state induced by daily intraplantar injections of PGE(2) in rats and its regulation in vivo by protein kinase A (PKA) and protein kinase C epsilon (PKC epsilon) as well. In the prostaglandin E(2) (PGE(2))-induced persistent hypernociception, the Na(v)1.8 mRNA in the dorsal root ganglia (DRG) was up-regulated. The local treatment with dipyrone abolished this persistent hypernociception but did not alter the Na(v)1.8 mRNA level in the DRG. Daily intrathecal administrations of antisense Na(v)1.8 decreased the Na(v)1.8 mRNA in the DRG and reduced ongoing persistent hypernociception. once the persistent hypernociception had been abolished by dipyrone, but not by Na(v)1.8 antisense treatment, a small dose of PGE(2) restored the hypernociceptive plateau. These data show that, after a period of recurring inflammatory stimuli, an intense and prolonged nociceptive response is elicited by a minimum inflammatory stimulus and that this pro-nociceptive state depends on Na(v)1.8 mRNA up-regulation in the DRG. in addition, during the persistent hypernociceptive state, the PKA and PKC epsilon expression and activity in the DRG are up-regulated and the administration of the PKA and PKC epsilon inhibitors reduce the hypernociception as well as the Na(v)1.8 mRNA level. In the present study, we demonstrated that the functional regulation of the Na(v)1.8 mRNA by PKA and PKC epsilon in the primary sensory neuron is important for the development of the peripheral pro-nociceptive state induced by repetitive inflammatory stimuli and for the maintenance of the behavioral persistent hypernociception. (C) 2008 Elsevier Inc. All rights reserved.
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Background and purpose: Cannabidiol (CBD) is a non-psychotomimetic compound from Cannabis sativa that induces anxiolytic- and antipsychotic-like effects in animal models. Effects of CBD may be mediated by the activation of 5-HT(1A) receptors. As 5-HT(1A) receptor activation may induce antidepressant-like effects, the aim of this work was to test the hypothesis that CBD would have antidepressant-like activity in mice as assessed by the forced swimming test. We also investigated if these responses depended on the activation of 5-HT(1A) receptors and on hippocampal expression of brain-derived neurotrophic factor (BDNF). Experimental approach: Male Swiss mice were given (i.p.) CBD (3, 10, 30, 100 mg.kg(-1)), imipramine (30 mg.kg(-1)) or vehicle and were submitted to the forced swimming test or to an open field arena, 30 min later. An additional group received WAY100635 (0.1 mg.kg(-1), i.p.), a 5-HT(1A) receptor antagonist, before CBD (30 mg.kg(-1)) and assessment by the forced swimming test. BDNF protein levels were measured in the hippocampus of another group of mice treated with CBD (30 mg.kg(-1)) and submitted to the forced swimming test. Key results: CBD (30 mg.kg(-1)) treatment reduced immobility time in the forced swimming test, as did the prototype antidepressant imipramine, without changing exploratory behaviour in the open field arena. WAY100635 pretreatment blocked CBD-induced effect in the forced swimming test. CBD (30 mg.kg(-1)) treatment did not change hippocampal BDNF levels. Conclusion and implications: CBD induces antidepressant-like effects comparable to those of imipramine. These effects of CBD were probably mediated by activation of 5-HT(1A) receptors. British Journal of Pharmacology (2010) 159, 122-128; doi:10.1111/j.1476-5381.2009.00521.x; published online 4 December 2009
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Heat shock proteins are molecular chaperones linked to a myriad of physiological functions in both prokaryotes and eukaryotes. In this study, we show that the Aspergillus nidulans hsp30 (ANID_03555.1), hsp70 (ANID_05129.1), and hsp90 (ANID_08269.1) genes are preferentially expressed in an acidic milieu, whose expression is dependent on the palA (+) background under optimal temperature for fungal growth. Heat shock induction of these three hsp genes showed different patterns in response to extracellular pH changes in the palA(+) background. However, their accumulation upon heating for 2 h was almost unaffected by ambient pH changes in the palA (-) background. The PalA protein is a member of a conserved signaling cascade that is involved in the pH-mediated regulation of gene expression. Moreover, we identified several genes whose expression at pH 5.0 is also dependent on the palA (+) background. These results reveal novel aspects of the heat- and pH-sensing networks of A. nidulans.
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Proteomic approaches have been useful for the identification of aberrantly expressed proteins in complex diseases such as cancer. These proteins are not only potential disease biomarkers, but also targets for therapy. The aim of this study was to identify differentially expressed proteins in diffuse astrocytoma grade II, anaplastic astrocytoma grade III and glioblastoma multiforme grade IV in human tumor samples and in non-neoplastic brain tissue as control using 2-DE and MS. Tumor and control brain tissue dissection was guided by histological hematoxylin/eosin tissue sections to provide more than 90% of tumor cells and astrocytes. Six proteins were detected as up-regulated in higher grade astrocytomas and the most important finding was nucleophosmin (NPM) (p < 0.05), whereas four proteins were down-regulated, among them raf kinase inhibitor protein (RKIP) (p < 0.05). We report here for the first time the alteration of NPM and RKIP expression in brain cancer. Our focus on these proteins was due to the fact that they are involved in the PI3K/AKT/mTOR and RAS/RAF/MAPK pathways, known for their contribution to the development and progression of gliomas. The proteomic data for NPM and RKIP were confirmed by Western blot, quantitative real-time PCR and immunohistochemistry. Due to the participation of NPM and RKIP in uncontrolled proliferation and evasion of apoptosis, these proteins are likely targets for drug development.
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Association between insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD) has been reported. This prompted us to evaluate the power of the insulin sensitivity index (ISI) in association with IGFBP-1 to identify IR early in obese children/adolescents. OGTT was performed in 34 obese/overweight children/adolescents. Glucose, insulin and IGFBP-1 were measured in serum samples and ISI was calculated. Considering the presence of three or more risk factors for IR as a criterion for IR, ISI <4.6 showed 87.5% sensitivity and 94.5% specificity in diagnosing IR. IGFBP-1 was lower in the group with ISI <4.6 (p <0.01). In this group, three patients had higher than expected IGFBP-1, suggesting hepatic IR, while three patients with ISI >4.6 showed very low IGFBP-1 levels. Conclusion: ISI <4.6 is a good indicator of early peripheral IR and, associated with IGFBP-1, can identify increased risk of hepatic IR. Low IGFBP-1 levels among non-IR children may indicate increased portal insulin levels.
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Context: Genetic factors that influence the response to recombinant human GH (rhGH) therapy remain mostly unknown. To date, only the GH receptor gene has been investigated. Objective: The aim of the study was to assess the influence of a polymorphism in the IGF-binding protein-3 (IGFBP-3) promoter region (-202 A/C) on circulating IGFBP-3 levels and growth response to rhGH therapy in children with GH deficiency (GHD). Design and Patients: -202 A/C IGFBP3 genotyping (rs2854744) was correlated with data of 71 children with severe GHD who remained prepubertal during the first year of rhGH treatment. Main Outcome Measures: We measured IGFBP-3 levels and first year growth velocity (GV) during rhGH treatment. Results: Clinical and laboratory data at the start of treatment were indistinguishable among patients with different -202 A/C IGFBP3 genotypes. Despite similar rhGH doses, patients homozygous for the A allele presented higher IGFBP-3 SD score levels and higher mean GV in the first year of rhGH treatment than patients with AC or CC genotypes (first year GV, AA = 13.0 +/- 2.1 cm/yr, AC = 11.4 +/- 2.5 cm/yr, and CC = 10.8 +/- 1.9 cm/yr; P = 0.016). Multiple linear regression analyses demonstrated that the influence of -202 A/C IGFBP3 genotype on IGFBP-3 levels and GV during the first year of rhGH treatment was independent of other variables. Conclusion: The -202 A allele of IGFBP3 promoter region is associated with increased IGFBP-3 levels and GV during rhGH treatment in prepubertal GHD children. (J Clin Endocrinol Metab 94: 588-595, 2009)
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Turkey coronavirus (TCoV) is a causative agent associated with poult enteritis and mortality syndrome (PEMS) in turkeys worldwide. The disease is an acute, highly contagious enteric disease that is characterized by depression, anorexia, diarrhea, and high mortality in commercial turkey flocks. The presence of TCoV in 12 intestinal-content samples, from turkey flocks aged between 10 and 104 days and exhibiting severe enteritis, was monitored during the period of 2004 to 2006. TCoV detection was accomplished by a reverse transcriptase-polymerase chain reaction (RT-PCR) through amplification of the 3` UTR region, followed by amplification of genes 3 and 5. Molecular characterization of the viruses was done through amplification of genes 3 and 5 and showed evidence of genetic similarity between them, although they differed from sequences of other TCoVs described in the literature. In relation to gene 3, samples showed a greater relationship with chicken infectious bronchitis virus (IBV), while gene 5 showed greater identity with pheasant coronavirus (PhCoV). Our results suggest that the strategy of amplification of the 3` UTR region, followed by sequencing of genes 3 and 5, has proven to be an effective means of detecting TCoV in intestinal contents.
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Squamous cell carcinoma of the oral cavity (OSCC) is a malignancy characterized by a high degree of local aggression and metastasis to cervical lymph nodes. Tetraspanins are proteins with functional roles in a wide array of cellular processes and are reported to be associated with tumor progression. The present study investigated the expression of the CD9, CD37, CD63, CD81 and CD82 tetraspanins in OSCC using immunohistochemistry (IHC) and quantitative Real Time-PCR (qRT-PCR). Tissue microarray (TMA) analysis of samples from 179 cases of OSCC and 10 normal samples oral mucosa were evaluated immunomorphologically. We analyzed CD9 and CD82 expression by qRT-PCR in 66 OSCC cases and 4 normal samples of oral mucosa. Expression of CD63, CD37 and CD81 was not detected in the samples studied. CD82 was downregulated or negative in 127 of 179 (80%) specimens; no correlation was observed between CD82 expression, clinicopathological parameters, disease-free survival and 5-year overall survival. CD9 expression was downregulated or negative in 75 of 129 (42%) OSCC samples. Loss of CD9 expression in OSCC samples correlated with the incidence of lymph node metastasis (p = 0.017). Disease-free survival and the 5-year overall survival of patients with downregulated or negative CD9 expression were significantly lower than in patients with positive CD9 expression (p = 0.010 and p = 0.071, respectively). No correlation was found between CD9 or CD82 expression and clinicopathological parameters by qRT-PCR. Our results suggest that the downregulation or lack of expression of the CD9 protein might indicate a more aggressive of OSCC. (C) 2009 Elsevier Ltd. All rights reserved.
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Glial fibrillary acidic protein (GFAP) is a member of the intermediary filament protein family. It is an important component of astrocytes and a known diagnostic marker of glial differentiation. GFAP is expressed in other neural tumors and pleomorphic adenoma and, less frequently, in cartilage tumors, chordomas, and soft tissue myoepitheliomas. The aim of this study was to evaluate the role of GFAP and its reliability in nonglial tumors as an immunohistochemical marker. We evaluated GFAP gene and protein expression using Q-PCR and immunohistochemistry, respectively, in 81 and 387 cases of soft tissue, bone tumors, and salivary pleomorphic adenomas. Immunohistochemistry staining for GFAP was observed in all osteosarcomas (8 cases), all pleomorphic adenomas (7 cases), in 5 of 6 soft tissue myoepitheliomas, and in 21 of 76 chondrosarcomas. By Q-PCR, GFAP was highly expressed in pleomorphic adenomas and, to a lesser extent, chondrosarcomas, soft tissue myoepitheliomas, and chondroblastic osteosarcomas. The results that we obtained by immunohistochemistry and Q-PCR were well correlated. GFAP is a potential marker for tumors with cartilaginous differentiation, supported by evidence that GFAP is expressed in certain cases of myoepithelial tumors by immunohistochemistry, including soft tissue myoepitheliomas, which are related to cartilaginous differentiation. These findings contribute significantly to the diagnosis of soft tissue myoepitheliomas with cartilaginous differentiation and chondroblastic osteosarcoma in mesenchymal tumors. Modern Pathology ( 2009) 22, 1321-1327; doi: 10.1038/modpathol.2009.99; published online 7 August 2009
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Aim: The aim of the present study was to assess the influence of the chemical characteristics and roughness of titanium surfaces on the viability, proliferation and differentiation of osteoblast-like cells cultured in a medium supplemented with recombinant human bone morphogenetic protein-7 (rhBMP-7). Material and methods: Osteo-1 cells were grown on titanium disks presenting with the following surfaces: (1) machined, (2) coarse grit-blasted and acid-attacked (SLA) and (3) chemically modified SLA (SLAmod) in the absence or presence of 20 ng/ml rhBMP-7 in culture medium. The viability and number of osteo-1 cells were evaluated after 24 h. Analyses of total protein content (TP) and alkaline phosphatase (AP) activity at 7, 14 and 21 days, collagen content at 7 and 21 days and mineralized matrix formation at 21 days were performed. Results: Cell viability (P=0.5516), cell number (P=0.3485), collagen content (P=0.1165) and mineralized matrix formation (P=0.5319) were not affected by the different surface configurations or by the addition of rhBMP-7 to the medium. Osteo-1 cells cultured on SLA surfaces showed a significant increase in TP at 21 days. The ALPase/TP ratio (P=0.00001) was affected by treatment and time. Conclusion: The results suggest that the addition of rhBMP-7 to the culture medium did not exert any effect on the viability, proliferation or differentiation of osteoblast-like cells grown on the different surfaces tested. All titanium surfaces analyzed allowed the complete expression of the osteoblast phenotype such as matrix mineralization by osteo-1 cells.
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Adenomas are the precursors of most colorectal cancers. Hyperplastic polyps have been linked to the subset of colorectal cancers showing DNA microsatellite instability, but little is known of their underlying genetic etiology. Using a strategy that isolates differentially methylated sequences from hyperplastic polyps and normal mucosa, we identified a 370-bp sequence containing the 5' untranslated region and the first exon of a gene that we have called HPP1. Rapid amplification of cDNA ends was used to isolate HPP1 from normal mucose. Using reverse transcription-PCR, HPP1 was expressed in 28 of 30 (93%) normal colonic samples but in only seven of 30 (23%) colorectal cancers (P < 0.001). The 5' region of HPP1 included a CpG island containing 49 CpG sites, of which 96% were found to be methylated by bisulfite sequencing of DNA from colonic tumor samples. By COBRA analysis, methylation was detected in six of nine (66%) adenomas, 17 of 27 (63%) hyperplastic polyps, and 46 of 55 (84%) colorectal cancers. There was an inverse relationship between methylation level and mRNA expression in cancers (r = -0.67; P < 0.001), and 5-aza-2-deoxycytidine treatment restored HPP1 expression in two colorectal cancer cell lines. In situ hybridization of HPP1 indicated that expression occurs in epithelial and stromal elements in normal mucosa but is silenced in both cell types in early colonic neoplasia. HPP1 is predicted to encode a transmembrane protein containing follistatin and epidermal growth factor-like domains. Silencing of HPP1 by methylation may increase the probability of neoplastic transformation.
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Background Distraction osteogenesis (DO) is a method of producing new bone directly from the osteotomy site by gradual traction of the divided bone fragments. Aim The purpose of the present study was to evaluate histomorphometrically whether acute DO would constitute a viable alternative to the conventional continuous distraction treatment and also to verify the capacity of a recombinant human BMP (rhBMP-2) associated with monoolein gel to stimulate bone formation in the acute distraction process. Materials and methods Forty-eight Wistar rats were assigned to three groups: Group 1, treated at a conventional continuous distraction rate (0.5 mm/day), Group 2, treated with acute distraction of 2.5 mm at the time of the surgical procedure, and Group 3, subjected to acute distraction associated with rhBMP-2. The animals from each experimental group were killed at the end of the second or fourth post-operative weeks and the volume fraction of newly formed bone trabeculae was estimated in histological images by a differential point-counting method. Results The results showed that after 2 and 4 weeks, bone volumes in the rhBMP-2 group were significantly higher than in the other groups (P < 0.05), but no significant difference was observed in the volume fraction of newly formed bone between the continuous and acute DO groups. Conclusion In conclusion, the study indicates that rhBMP-2 can enhance the bone formation at acute DO, which may potentially reduce the treatment period and complications related to the distraction procedure. To cite this article:Issa JPM, do Nascimento C, Lamano T, Iyomasa MM, Sebald W, de Albuquerque Jr RF. Effect of recombinant human bone morphogenetic protein-2 on bone formation in the acute distraction osteogenesis of rat mandibles.Clin. Oral Impl. Res. 20, 2009; 1286-1292.doi: 10.1111/j.1600-0501.2009.01799.x.